Airdrie's bid to achieve Championship football next season ended at the final hurdle against Morton in the play-off final.
The Diamonds produced a brilliant run of just one defeat in eleven games leading into the final but they couldn't replicate that form against Morton.
Robbie Muirhead was the Ton hero in the first-leg with a stoppage-time winner and he scored an unbelievable goal to give the Greenock side the lead in the second-leg after 12 minutes.
Airdrie were under the cosh for the majority of the first half and Gary Oliver added a second just before the break.
The Diamonds improved after the interval but they failed to truly test Scott Fox and Muirhead scored his second of the night on 78 minutes to wrap up the win.
Ian Murray named two changes from the first-leg with Thomas Robert and Josh Kerr replacing Paul McKay and the experienced Dale Carrick.
Morton boss Gus MacPherson made just one change with Reece Lyon coming in for the injured Kyle Jacobs.
Muirhead's injury time header handed the 'Ton a one-goal advantage heading into the second-leg at Cappielow.
Morton were backed by 500 fans - plus a couple of hundred supporters watching outside the ground - as they welcomed their support back for the first time this season.
The Diamonds faced an uphill task after losing at home and they were hit with a devastating blow on 12 minutes when Muirhead arrowed a sensational strike on the half-volley into the top corner.
The ball fell invitingly to the former Hearts man and he unleashed an unstoppable left-footed effort past Max Currie from 20 yards to double Morton's aggregate lead.
Airdrie were living dangerously and they almost conceded a second when Cameron Salkeld dragged a shot just wide of the post just minutes after Muirhead's opener.
Airdrie struggled to gain a foothold during the opening twenty minutes with Callum Gallagher cutting an isolated figure up front.
The hosts had a strong claim for a penalty turned away by referee Alan Muir when Salkeld's cross hit Leon McCann's arm from close range.
Airdrie managed to weather the storm but they failed to create a single chance in the first-half with Kyle Turner, uncharacteristically, delivering a few disappointing free-kicks.
Morton grabbed their second of the night on 43 minutes to establish a three-goal aggregate lead to essentially preserve their Championship status.
Lewis Strapp's looping effort rebounded off the bar for Gary Oliver to head into an empty net to leave Airdrie with a mountain to climb.
Airdrie created their best opportunity of the game just after the break when Thomas Robert released an inch-perfect pass through to Gallagher but Michael Ledger made an excellent recovery block.
From the resulting corner, the Diamonds managed their first effort on target but Sean Crighton's header was straight at Scott Fox.
Morton were completely dominant during the first-half but Airdrie improved after the break and Robert went close to pulling a goal back on 67 minutes.
Airdrie committed men forward in search of a lifeline but they were almost hit by a devastating counter but Callum Fordyce recovered well.
Muirhead was the star of the show across both legs and he grabbed his second of the night - and third of the tie - when he tapped home on 78 minutes after Currie parried Stephen McGinn's powerful shot.
It proved to be a disappointing end to a decent season for Airdrie and they face strong competition from Queens Park, Cove Rangers and Falkirk in League One next season.
Morton: Fox, Ledger, Fjortoft, McLean, McGinn, Muirhead, Oliver, Salkeld(Nesbitt, 69'), Strapp, Lyon, Blues
Subs: Wylie, Hynes, Colville, McGuffie, Orsi, McGinty
Goals: Muirhead 12' & 78', Oliver 43'
Airdrie: Currie, McCann, Kerr(Thomson, 24'), Crighton, Fordyce, McKay(Roy 58'), Walker(Ritchie 84'), Turner, O'Reilly, Robert, Gallagher
Subs: Sabatini, McNeil, Stokes
Booked: McKay 53', O'Reilly 58', McCann 90'
Follow Lanarkshire Live Sport on Twitter via @LanLiveSport, like us on Facebook or find us on Instagram for the latest sports news, pictures and video
